A variety of biopsy needles and similar devices for obtaining a tissue sample from a patient are known. Commonly, such devices include a thin needle or stylet that can be inserted into the skin of the patient near the location of tissue to be sampled, such as suspected malignancies or other tissue of interest. Once the distal end or other cutting portion of the needle or stylet is within the tissue of interest, a portion of the tissue is excised and captured. The needle or stylet is withdrawn with the tissue sample, which can be retrieved from the device and studied.
Such products have proven quite effective in obtaining tissue in a minimally-invasive manner and with minimal discomfort to the patient. Their lightweight nature, combined with their ease of operation and reusability, make them excellent for sampling tissue that may present or indicate a health problem to the patient.
Biopsy needles designed to obtain samples of a fixed length are familiar, and in many cases that setting is either for a length of sample of 10 mm or 20 mm. Biopsy needles or other tissue sampling devices have been proposed that permit a variation of sample size, as by allowing the user to select or set the throw length to particular discrete settings for example. It can occur that the user forgets the setting he or she has chosen, or whether he or she has properly cocked or set the device for taking a sample at all. Further, the user may wish to reconfirm the setting as a part of his or her best practices. There remains a need for tissue sampling devices capable of obtaining varying amounts of tissue depending on a particular situation, and which permits easy confirmation that the device is set for a desired sample size.